Re: [PATCH 2/8] f2fs: add tracepoints for inode operations

[Namjae Jeon]

2013/2/19 Steven Rostedt <rostedt@xxxxxxxxxxx>:
> On Tue, 2013-02-19 at 11:33 +0900, Namjae Jeon wrote:
>> From: Namjae Jeon <namjae.jeon@xxxxxxxxxxx>
>
>> +TRACE_EVENT(f2fs_unlink_exit,
>> +     TP_PROTO(struct dentry *dentry, int ret),
>> +
>> +     TP_ARGS(dentry, ret),
>> +
>> +     TP_STRUCT__entry(
>> +             __field(ino_t,  ino)
>> +             __field(dev_t,  dev)
>> +             __field(int,    ret)
>> +     ),
>> +
>> +     TP_fast_assign(
>> +             __entry->ino            = dentry->d_inode->i_ino;
>> +             __entry->dev            = dentry->d_inode->i_sb->s_dev;
>> +             __entry->ret            = ret;
>> +     ),
>> +
>> +     TP_printk("dev %d,%d ino %lu ret %d",
>> +               MAJOR(__entry->dev), MINOR(__entry->dev),
>> +               (unsigned long) __entry->ino,
>> +               __entry->ret)
>> +);
>> +
>>  #endif /* _TRACE_F2FS_H */
>>
>>   /* This part must be outside protection */
>
> If at all possible, try to combine as many tracepoints as possible by a
> class. A TRACE_EVENT() is really a DECLARE_EVENT_CLASS();
> DEFINE_EVENT(); pair that totals about 5k per TRACE_EVENT(). The
> DECLARE_EVENT_CLASS() being the majority of that. A DEFINE_EVENT() adds
> approximately 250 bytes each. Thus, combining the above with the
> TRACE_EVENT() from the previous patch:
>
> +TRACE_EVENT(f2fs_sync_file_exit,
> +       TP_PROTO(struct inode *inode, int ret),
> +
> +       TP_ARGS(inode, ret),
> +
> +       TP_STRUCT__entry(
> +               __field(int,    ret)
> +               __field(ino_t,  ino)
> +               __field(dev_t,  dev)
> +       ),
> +
> +       TP_fast_assign(
> +               __entry->ret            = ret;
> +               __entry->ino            = inode->i_ino;
> +               __entry->dev            = inode->i_sb->s_dev;
> +       ),
> +
> +       TP_printk("dev %d,%d ino %lu ret %d",
> +                 MAJOR(__entry->dev), MINOR(__entry->dev),
> +                 (unsigned long) __entry->ino,
> +                 __entry->ret)
> +);
>
> into:
>
> DECLARE_EVENT_CLASS(f2fs_dev_inode_ret,
>        TP_PROTO(struct inode *inode, int ret),
>
>        TP_ARGS(inode, ret),
>
>        TP_STRUCT__entry(
>                __field(int,    ret)
>                __field(ino_t,  ino)
>                __field(dev_t,  dev)
>        ),
>
>        TP_fast_assign(
>                __entry->ret            = ret;
>                __entry->ino            = inode->i_ino;
>                __entry->dev            = inode->i_sb->s_dev;
>        ),
>
>        TP_printk("dev %d,%d ino %lu ret %d",
>                  MAJOR(__entry->dev), MINOR(__entry->dev),
>                  (unsigned long) __entry->ino,
>                  __entry->ret)
> );
>
> DEFINE_EVENT(f2fs_sync_file_exit,
>        TP_PROTO(struct inode *inode, int ret),
>        TP_ARGS(inode, ret));
>
> DEFINE_EVENT(f2fs_unlink_exit,
>        TP_PROTO(struct inode *inode, int ret),
>        TP_ARGS(inode, ret));
>
> You can save ~4750 bytes. Note, you will need to pass the inode instead
> of the dentry into f2fs_unlink_exit(), but you don't use the dentry
> anyway.
Hi Steven.
Thanks for review :). I will update patches as your advice.


> -- Steve
>
>
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